Introduction to Human-Computer Interaction

Transcription

1 Introduction to Human-Computer Interaction Designing Interactive Systems Lecture 1 Nadia Boukhelifa nadia.boukhelifa@inria.fr with acknowledgements to: Petra Isenberg, Anastasia Bezerianos, Anthony Tang, Nic Marquardt, Tobias Isenberg, Raimund Dachselt

2 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 2 Photograph courtesy of Penelope Sanderson

3 bad interaction design is everywhere Photographs courtesy of Penelope Sanderson Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 3

4 bad interaction design is everywhere Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 4

5 bad interaction design is everywhere Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 5

6 bad interaction design is everywhere Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 6

7 This Is What Happens When You Let Developers Create UI Jeff Atwood (Co-Founder StackOverflow) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 7

8 bad interaction design can be harmful in harmless cases just to your general sense of well-being Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 8

9 bad interaction design can be harmful Money A $200 withdrawal turns into $20000 Bad font choice, looks like. Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 9

10 bad interaction design can be harmful Lives: Therac-25 Radiation Machine Massive doses of radiation led to several deaths The system noticed that something was wrong and halted the X-ray beam, but merely displayed the word "MALFUNCTION" followed by a number from 1 to 64. The user manual did not explain or even address the error codes, so the operator pressed the P key to override the warning and proceed anyway. Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 10

11 but, I wouldn t make those mistakes! maybe, but you re not the only one working on most projects. Your team might still make that mistake. here s the problem: you are typically not the user. you have your own biases. Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 11

12 summary interaction design is everywhere good interaction design is hard poorly designed things have big consequences good design practices can help you re going to be a good designer Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 12

13 course objectives learn ways to address interaction design problems learn how to understand users learn how to develop design representations work as part of an interaction design team involves hands-on experience with multiple design methods: involving users, prototyping, testing Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 13

14 introduction: me instructor: Nadia Boukhelifa post-doctoral researcher at INRIA Ph.D. in Computer Science from University of Kent research in Information Visualization / HCI office: at Université Paris Sud / Bâtiment Claude Shannon (plateau de Saclay) me for an appointment Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 14

15 basic course information website readings / slides posted online at the main website 09:45 11:15 (lecture 1-3, 5-7) 14:00 15:30 (lecture 4, Tuesday!) S109 11:30 13:00 (lab 1-3, 5-7) 15:45 17:15 (lab 4, Tuesday!) S109 Lecture Break Labs Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 15

16 Course outline January 15 Lecture: Introduction to HCI Tutorial: Group formation, picking projects January 19 Lecture: User requirements analysis Tutorial: Conducting a requirements analysis Hand in project component I February 2 Lecture: Sketching and storyboards Tutorial: Sketching and brainstorming Hand in project component II Febuary 3 Lecture: Prototyping Tutorial: Planning a high-fidelity prototype Feb 23 Lecture: Interaction Design Tutorial: Development of high-fidelity prototype Hand in project component III March 2 Lecture: Usability evaluation Demo project component IV March 9 Lecture: Information Visualization Tutorial: Heuristic evaluation March 16 Exam Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 16

17 assessment Class participation: 10% Project: 40% Exam: 50% Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 17

18 assessment participation (10%) treat everyone with respect be constructive be prepared for class let the instructor know if you cannot attend ask challenging questions, contribute with comments help your classmates / project team Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 18

19 assessment project 40% opportunity for you to engage in hands-on interaction design with a real project project teams of 3 (one group of 4) Component I - Group Formation & Topic Choice Component II - User Requirements Component III - Low-Fidelity Prototype Component IV - High-Fidelity Prototype Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 19

20 labs will explain the project components hands-on activities towards your projects Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 20

21 Acknowledgements Lecture slides include material from: Anthony Tang (University of Calgary) Nicolai Marquart (City University London) Anastasia Bezerianos (Université Paris Sud) Raimund Dachselt (University of Dresden) Tobias Isenberg (INRIA) Petra Isenberg (INRIA) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 21

22 Further readings Helen Sharp, Yvonne Rogers, Jenny Preece, Interaction Design: Beyond Human-Computer Interaction, Wiley, 2nd Edition, 2007, ISBN , Bill Buxton: Sketching User Experiences - Getting the Design Right and the Right Design. Morgan Kaufmann, 2007, ISBN Educating us in creativity and design [Shne05] Shneiderman, B., Plaisant, C.; Designing the User Interface; Pearson Addison-Wesley, 4th edition, 2005, ISBN Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 22

23 Questions? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 23

24 Lecture 1 WHAT IS HCI AND WHERE DO WE COME FROM? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 24

25 What is HCI? Human-computer interaction is a discipline concerned with the design, evaluation and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them [ACM] Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 25

26 We focus on designing interactive systems = [ ] developing interactive products that are easy, effective, and pleasurable to use from a user s perspective Rogers, Sharp, & Preece, 2011 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 26

27 hci is multidisciplinary Computer Science Artificial Intelligence Design Cognitive Sciences HCI Ergonomics Engineering Graphical Arts Psychology Social Sciences (Sociology, Anthropology) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 27

28 what is an interactive system? interaction devices user interfaces responsive software Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 28

29 what is a user interface (UI)? part of an interactive system that: represents its internal state on output peripherals captures & manages input from input peripherals the medium through which the communication between human and computer takes place through the interface user actions are translated into instructions that are comprehensible for the computer computer outputs are coherently edited for the user so that he/she can react on them [Bowm+04] Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 29

30 user interface The DEC VT100, a widely emulated computer terminal image source wikipedia Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 30

31 graphical user interface (GUI) interface + to that uses output peripherals (screen, projector) some input peripherals (mouse, pen) that provide relative positions w.r.t. the output peripherals allow reference to aspects on the interface using pointing (thus linking input/output) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 31

32 graphical user interface image source wikipedia Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 32

33 UI is responsible for approx. 50% of the design, implementation and maintenance time + code size important part of the software development Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 33

34 what is an interaction technique? A method which enables the user to carry out a task by means of the user interface. Comprises hardware and software components Software component responsible for transfer of device information into actions and for the issue of (graphical, acoustic, haptic) feedback [Bowm+04]. Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 34

35 drag and drop image source wikipedia Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 35

36 usability aim is to make things that meet users needs there are many ways to meet needs usability is concerned with optimizing interactions Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 36

37 usability goals effective to use efficient to use safe to use have good utility easy to learn easy to remember how to use Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 37

38 the user experience all aspects of the user s interaction with the product: how it is perceived, learned, and used important questions: what are the important qualities of the intended experience? fast and efficient vs. slow and leisurely interactions Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 38

39 in this course we will be concerned with all these aspects interactive systems graphical user interfaces interaction techniques usability user experience Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 39

40 but first we need to learn where we re coming from a brief history of human-computer interfaces Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 40

41 the history of interfaces Grudin (1990) The computer reaches out: The historical continuity of interface design Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 41

42 History of the development of UIs [vdam97] No predictable, steady UI improvements, like e.g. for Moore s Law More like a punctuated equilibrium (Steven Jay Gould) long periods of stability, interrupted through rapid changes Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 42

43 Moore s Law Gordon Moore (Intel): 1965 The complexity for minimum component costs has increased at a rate of roughly a factor of two per year... Certainly over the short term this rate can be expected to continue, if not to increase. Over the longer term, the rate of increase is a bit more uncertain, although there is no reason to believe it will not remain nearly constant for at least 10 years. Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 43

44 Moore s Law bang on so far image source wikipedia Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 44

45 history of GUIs Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 45

46 the history of interfaces Phase 1,2 interaction by programming 1950s 60s Batch mode Punch cards Line printer Not interface, no menus Colossus Mark 2 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 46

47 but there were revolutionary thinkers much earlier MEMEX and Hypertext (1945) Vannevar Bush: As We May Think Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 47

48 The Memex user interface A memex is a device in which an individual stores all his books, records, and communications, and which is mechanized so that it may be consulted with exceeding speed and flexibility. User interface: Translucent screens (displays) A keyboard, buttons and levers A camera ( analog scanner ) place to leave notes and comments dual projectors with ability to cross-reference text all human knowledge stored on mico-film human interface through buttons Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 48

49 The Memex Legacy Predicted personal computers, hypertext, the internet, the www, speech recognition, online encyclopedias "Wholly new forms of encyclopedias will appear, readymade with a mesh of associative trails running through them, ready to be dropped into the memex and there amplified." Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 49

50 Sketchpad Ivan Sutherland (1963) 1960s usually computers dealt with batches of jobs and used punched cards for input exception: TX-2 computer at MIT punched card Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 50

51 Sketchpad Ivan Sutherland (1963) PhD thesis at MIT 1 st graphical interface graphical screen pointing devices (optical pen) and buttons design, zoom, copy-paste, icons, geometric constraints Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 51

52 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 52

53 Sketchpad Ivan Sutherland (1963) Ivan Sutherland received for Sketchpad: the ACM Turing Award (1988) (thought of as the Nobel prize for computing) the Kyoto Prize (2012) (regarded as Japanese equivalent of Nobel prize) Sketchpad influenced: CAD development of computer graphics GUI development object oriented programming Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 53

54 the history of interfaces Phase 3 commands with parameters 1960s-1980s End users (time-sharing) Human factors, cognitive psychology, graphic design Time sharing creates the illusion of a personal machine User can afford to think at the terminal Focus on user behaviour and productivity Computer mediated human-human interaction (CSCW) Messages / Shared file systems Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 54

55 Douglas Engelbart NLS (1968) Stanford Research Institute developed system to augment human intellect and use a network, wanted to turn the idea of Memex into reality (online System) invention of mouse, keyboard & function buttons hypertext links (remember Vannevar Bush (1945)) collaborative work, video-conference, document sharing Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 55

56 The Mother of All Demos took 90 minutes SF convention center (~1000 attendees) first time an integrated system for manipulating text onscreen was presented publicly demonstrated with help of geographically distributed team Engelbart was seated next to the screen at the controls of an online workstations whose display output was projected on the screen in the convention center Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 56

57 ffwd to discussion of the mouse Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 57

58 the history of interfaces Phase 4 GUIs - WIMP 1980s- Personal computers Many end-users More cognitive psychology, graphic design point-and click WIMP = windows, icons, menus, pointers (usually mouse) Phase 5 post-wimp 1990s- multiple, simultaneous input and outputs often more than one user different UI styles and terms beyond mouse and keyboard Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 58

59 history of GUIs Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 59

60 history of GUIs Xerox PARC = Palo Alto Research Center created in 1970 PARC grouped divers talent, interested in photocopying but also desktop computers 3 researchers/engineers won a Turing award Known for inventing OO Programming (Smalltalk) Ethernet Portable computers Laser printers WIMP : Windows, Icons, Menus & Pointers Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 60

61 Xerox Alto personal computer (1973) first to demonstrate desktop metaphor + GUI one of the first to use a mouse after sketchpad bitmapped screen not a commercial product GUI used windows, icons and menus (first fixed drop-down menu) first WYSIWYG cut & paste editor Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 61

62 Xerox Star (1981) followed from Alto as commercial product $16,500 first personal computer with GUI to be sold commercially (no financial success) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 62

63 Apple Lisa (1978, released 1983) second personal computer with GUI to be sold commercially drop-down menu bar, windows, multiple tasking, a hierarchical file system, the ability to copy and paste, icons, folders and a mouse US$9,995 (approximately $23,426 in today's dollars Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 63

64 Apple Macintosh (1984) $2,495 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 64

65 Apple Macintosh (1984) commercial success, more mature aggressive price ($2,500) accessible to larger public menu bar, modal dialog boxes and visible UI toolkit to help external developers $2,495 detailed style guides to help consistence between apps three key applications: Finder, MacPaint, MacWrite Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 65

66 Apple Macintosh (1984) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 66

67 MS Windows (1983) Microsoft Windows 1.01 Announced in 1983 by Bill Gates (Microsoft) 1987 released for IBM computers Large disappointment: lack of icons, too much reliance on mouse pointing, slow, lack of tutorials Windows Overlapping windows Mac-like icons Long court battle between Microsoft and Apple (ruled in favor of MS) Windows 3.1 Commercial success 40% market share Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 68

68 Desktop interface ( ) more power and new uses (network), but still lots of interfaces based on WIMP Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 69

69 what do we envision next? from Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 70

70 what do we envision next? from Minority Report, 2002 Twentieth Century FOX and Dreamworks Pictures Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 71

71 where are we now? entering post-wimp era Augmented / mixed reality Wearable UIs Tangible user interfaces Touch UIs Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 72

72 The Problem WHY IS IT DIFFICULT TO DESIGN GOOD UIS? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 73

73 Why is design hard? Everyone is different Age, knowledge, skill, ability, background People appropriate technology unexpectedly Designer s fallacy: that a designer can design into a technology, its purposes and uses Contexts of use may differ than what we expect Smartphone app use in the early days, and now Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 74

74 Appropriation In action Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 75

75 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 76

76 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 77

77 Why is design hard? We ve never seen it before We aren t the people using it We can t anticipate how people will use it Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 78

78 Why is design hard? Judging/predicting which designs will be successful is difficult Way more is possible than what is good Design involves making trade-offs Good designs are non-obvious Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 79

79 Why is design hard? People make errors slips: unintended action [motor action] mistakes: incorrect action [cognitive goal] Exercise: classify these Mistyping an address Clicking on a heading that isn t clickable Clicking Save instead of Open Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 80

80 Core design skills To synthesize a solution from all of the relevant constraints, understanding everything that will make a difference to the result To frame, or reframe, the problem and objective To create and envision alternatives. To select from those alternatives, knowing intuitively how to choose the best approach. To visualize and prototype the intended solution Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 81

81 The user is not like me Familiarity with the interface problems being solved Confidence Designer s setting vs. user s setting Designers have different skills (perceptual, cognitive, or domain) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 82

82 Are there processes that can be followed? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 83

83 the user-centered approach early focus on users and tasks empirical measurement iterative design Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 84

84 four basic activities 1. establishing requirements 2. designing alternatives 3. prototyping 4. evaluating Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 85

85 the design lifecycle Establishing requirements Designing alternatives Evaluating Prototyping Final product Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 86

86 Iterative Process Harper et al., 2008 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 87

87 Iterative Process what human values do we wish to design for? what are the various morale, personal, and social impacts of the proposed system? Harper et al., 2008 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 88

88 practical issues who are the users? what are their needs? how do we generate alternatives? how to choose among alternatives? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 89

89 users needs users rarely know what is possible look at existing tasks: their context what information do they require? who collaborates to achieve the task? why is the task achieved the way it is? envisioned tasks: can be rooted in existing behaviour can be described as future scenarios Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 90

90 involving users member of the design team participatory design approach full- or part-time members, for short- or long-term periods of the project occasional consultation interview users to identify needs get feedback on prototypes through user testing Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 91

91 requirements understand as much as possible about users, their tasks, and context of use in order to produce a stable set of requirements Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 92

92 Break Class will resume in minute(s) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 93

93 Deep Dive: IDEO s redesign of the Shopping Cart Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 94

94 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 95

95 Idea Generation LAB 1 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 96

96 Deep Dive Discussion 15 mins Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 97

97 good design RARELY happens alone Others are needed to help generate ideas, give feedback, etc. Diversity of backgrounds, skills, and experiences are needed Today s lab is about understanding that group process and facilitating team formation Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 98

98 breakout Session Find teammates now you can either self-assign (research does not recommend this) we an do a small exercise to select groups (research recommends this) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 99

99 group selection exercise 5mins You are designing a new interface for paying a parking ticket in a parking garage. Which of the following aspects would you choose to work on: a) finding out how people currently pay b) building an example mockup c) designing the hardware d) designing the software e) something else write your name and answer on a piece of paper and give it to the instructor Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 100

100 project we will work on during the course many people suffer from information overload The goal of the project is to figure out an application running on a certain device that can show us the information we need at a glance Currently many apps send us s or push notifications to make us aware of information we need. This is not very creative - how can we do better? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 101

101 Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 102

102 Breakout Session 15 mins Find with your group 10 examples of situations where people have to deal with information overload Write down: who are the people what is the information they deal with Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 103

103 Breakout Session 20 mins Pick your favorite situation and create some sketches What is the problem (or problems) that needs to be addressed? Where would an app to solve the problem be used? What is the current situation? What are your assumptions about this problem? Assumptions are things you have not empirically backed up (e.g. security of children in a shopping cart is an issue before you ve read any studies about the topic) What would you need to find out? Who would you ask? How would you ask? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 104

104 Breakout Session 5 min talks 5 minute talks walk everyone through the charts you constructed 2 minute questions Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 105

105 Group Discussion mins Place the sketches of the different project ideas around the room Walk around, and discuss these project ideas with others Use sticky notes to add a variation to that project idea e.g. variations for communication system for families: (1) between homes; (2) between grandma and baby; (3) within a home If you would like to change groups, discuss with others Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 106

106 Project Component I - Deliverables Get, buy, reuse a binder and in it put a piece of paper with the names & addresses of all team members a grading sheet (download from website) a description of your project idea (details see website and grading sheet) a description of users and stakeholders who is impacted in one way or another by your system? Hand the binder in at the beginning of the next lab! Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 107

107 In the remaining time begin with your deliverable flash our your project idea Problems to think of in this space: What should the device show? , weather, calendar, news,...? When should information be shown? How important is the context of use to what is being shown? How does the size of the screen influence what should be shown? What would alerts look like, would they be needed? What would the display look like for specialists in an area (e.g. if you pick musicians would John Lennon's display look different than Michael Jackson's)? Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 108

108 Acknowledgements Lecture slides include material from: Petra Isenberg (INRIA) Anthony Tang (University of Calgary) Nicolai Marquart (City University London) Anastasia Bezerianos (Université Paris Sud) Raimund Dachselt (University of Dresden) Tobias Isenberg (INRIA) Introduction to HCI Ecole Centrale 2015 Nadia Boukhelifa 109